An image-acquiring equipment with camera with linear sensor is described, having a telecentric optical objective whose main lens 23 is of the cylindrical type, placed in the same way as of the main lens of a known telecentric optics; the lens 23 can be of an a-cylindrical type, with profile computed for removing the cylindrical aberration; the optical assembly 13 for forming a real image 16 on the sensor 26 of the linear camera can be replaced with an optics of the photographic type, obtaining the best possible exploitation of the opening A of the main lens 23, greatly simplifying the construction of the telecentric optics; the image-acquiring equipment comprises a telecentric optics 27, a lamp 34 and a camera 24 of the linear or array type, and is pertaining to a viewing system for dimensional, geometric, or metrological checks.

An image-acquiring equipment with camera with linear sensor is described, having a telecentric optical objective whose main lens 23 is of the cylindrical type, placed in the same way as of the main lens of a known telecentric optics; the lens 23 can be of an a-cylindrical type, with profile computed for removing the cylindrical aberration; the optical assembly 13 for forming a real image 16 on the sensor 26 of the linear camera can be replaced with an optics of the photographic type, obtaining the best possible exploitation of the opening A of the main lens 23, greatly simplifying the construction of the telecentric optics; the image-acquiring equipment comprises a telecentric optics 27, a lamp 34 and a camera 24 of the linear or array type, and is pertaining to a viewing system for dimensional, geometric, or metrological checks.

An internal-reflective telecentric lens system includes a first lens assembly, a reflector, and a second lens assembly. The first lens assembly includes a first lens. The second lens assembly includes a second lens, a third lens, and a fourth lens, that are disposed in sequence along a light path. The first lens assembly is configured to receive and output one or more light beams towards the reflector. The reflector is configured to reflect the light beams towards the second lens assembly. The second lens assembly is configured to receive and converge the light beams reflected by the reflector at a diaphragm between the second lens and the third lens, and transmit the light beams past the diaphragm through the third and the fourth lenses for imaging.

An internal-reflective telecentric lens system includes a first lens assembly, a reflector, and a second lens assembly. The first lens assembly includes a first lens. The second lens assembly includes a second lens, a third lens, and a fourth lens, that are disposed in sequence along a light path. The first lens assembly is configured to receive and output one or more light beams towards the reflector. The reflector is configured to reflect the light beams towards the second lens assembly. The second lens assembly is configured to receive and converge the light beams reflected by the reflector at a diaphragm between the second lens and the third lens, and transmit the light beams past the diaphragm through the third and the fourth lenses for imaging.

The invention relates to a hybrid objective having a fixed focal length, which has five lenses. The objective is suitable for use in a LIDAR measurement system. Moreover, the use of a bi-aspherical plastic lens for correcting the curvature of the image field and/or astigmatism and/or distortion of an imaging objective is proposed.

A projection system that can be incorporated in a projector includes a first lens unit that makes a screen (enlargement-side image formation plane), which is located on the enlargement-side, conjugate with an intermediate image and a second lens unit that makes the intermediate image conjugate with a reduction-side image formation plane, which is located on the reduction side. The first lens unit has positive power, and the second lens unit has negative power. A second-lens-unit intermediate-image-side first lens, which is provided in the second lens unit and closest to the intermediate image, has positive power. The following expression is satisfied:

−0.3≦fU1/fU2<0

where fU1 denotes the focal length of the first lens unit, and fU2 denotes the focal length of the second lens unit.

A projection system that can be incorporated in a projector includes a first lens unit that makes a screen (enlargement-side image formation plane), which is located on the enlargement-side, conjugate with an intermediate image and a second lens unit that makes the intermediate image conjugate with a reduction-side image formation plane, which is located on the reduction side. The first lens unit has positive power, and the second lens unit has negative power. A second-lens-unit intermediate-image-side first lens, which is provided in the second lens unit and closest to the intermediate image, has positive power. The following expression is satisfied:

−0.3≦fU1/fU2<0

where fU1 denotes the focal length of the first lens unit, and fU2 denotes the focal length of the second lens unit.

An image lens assembly system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The first lens element with negative refractive power has a convex object-side surface. The second lens element has positive refractive power. The third lens element has refractive power. The fourth lens element has refractive power. The fifth lens element has refractive power. The sixth lens element with refractive power is made of plastic material, wherein at least one surface of the sixth lens element is aspheric. The seventh lens element with refractive power made of plastic material has a concave image-side surface changing from concave in a paraxial region to convex in a peripheral region, and at least one surface thereof is aspheric.

A compact bi-telecentric device includes refractive lenses and takes in light from a grid of emitters at the object plane and images them to a grid of receivers. It provides the capacity to combine multiple wavelengths of emitters at the object plane into a single receiver. The device is quite compact, less than 25 mm in length from object to image, and having a maximum diameter for any element of less than 4 mm. The device includes four optical lens elements, three of which have a positive focal length and one of which has a negative focal length. The device includes at least one diffractive optical element. The lens elements are separated into two distinct groups which each have positive optical power, separated by an aperture stop which may or may not be enabled by a physical surface. A diffractive element enables wavelength division multiplexing and compensates for distortion from the bi-telecentric device.

A compact bi-telecentric device includes refractive lenses and takes in light from a grid of emitters at the object plane and images them to a grid of receivers. It provides the capacity to combine multiple wavelengths of emitters at the object plane into a single receiver. The device is quite compact, less than 25 mm in length from object to image, and having a maximum diameter for any element of less than 4 mm. The device includes four optical lens elements, three of which have a positive focal length and one of which has a negative focal length. The device includes at least one diffractive optical element. The lens elements are separated into two distinct groups which each have positive optical power, separated by an aperture stop which may or may not be enabled by a physical surface. A diffractive element enables wavelength division multiplexing and compensates for distortion from the bi-telecentric device.